DC1506A Linear Technology, DC1506A Datasheet - Page 11

• Manufacturer Part Number: DC1506A
• Description: LTC4361-1/LTC4361-2 Overvoltage/Overcurrent Protection Controller With Latchoff/Auto-Retry
• Manufacturer: Linear Technology
• Series: -r

Specifications of DC1506A

• Design Resources: DC1506 Design Files DC1506A Schematic
• Main Purpose: Overvoltage/Overcurrent Protection
• Embedded: No
• Utilized Ic / Part: LTC4361
• Primary Attributes: -
• Secondary Attributes: -
• Kit Application Type: Power Management
• Application Sub Type: Overvoltage Protection
• Features: Demonstrates Three Protection Schemes Selected At JP1, Provides Connection For USB Protection
• Lead Free Status / Rohs Status: Not applicable / Not applicable

APPLICATIONS INFORMATION
As the IN pin can withstand up to 80V, a high voltage N-
channel MOSFET can be used to protect the system against
rugged abuse from high transient or DC voltages up to the
BV
into the LTC4361 controlling a 60V rated MOSFET.
Input transients also occur when the current through the
cable inductance changes abruptly. This can happen when
the LTC4361 turns off the N-channel MOSFET rapidly in an
overvoltage or overcurrent event. Figure 7 shows an input
transient after an overcurrent. The current in L
V
C
1.3 • (BV
85V absolute maximum voltage rating of the LTC4361.
IN
OUT
DSS
to overshoot and avalanche the N-channel MOSFET to
. Typically, IN will be clamped to a voltage of V
of the MOSFET. Figure 6 shows a 50V input plugged
20V/DIV
5A/DIV
1V/DIV
I
CABLE
DSS
V
OUT
V
Figure 6. 50V Hot-Plug into the LTC4361
IN
FDC5612
R
R
of Si1470DH) = 45V. This is well below the
IN
SENSE
= 150mΩ, L
= 25mΩ, LOAD = 10Ω, C
IN
= 0.7μH
5μs/DIV
OUT
= 10μF
436112 F06
IN
will cause
OUT
+
The single, nonrepetitive, pulse of energy (E
by the MOSFET during this avalanche breakdown with a
peak current I
For L
the I
the Si1470DH. So in most instances, the LTC4361 can
ride through such transients without a bypass capacitor,
transient voltage suppressor or other external components
at IN. Note that if an IN bypass capacitor is used, the V
transients will overshoot less but last longer. If V
below V
latch in the LTC4361-1 could be inadvertently reset.
Figure 7. Overcurrent Turn-Off and Resulting Input Transient
E
AS
AS
IN
20V/DIV
10V/DIV
= 0.5 • L
= 0.7μH and I
and E
5V/DIV
5A/DIV
I
IN(UVL)
V
CABLE
V
GATE
OUT
V
IN
LTC4361-1/LTC4361-2
AS
FIGURE 5 CIRCUIT
R
R
AS
IN
SENSE
for more than 10μs, the internal latch-off
IN
= 150mΩ, L
capabilities of most MOSFET’s including
is approximated by the formula:
• I
= 25mΩ, LOAD = 10Ω, C
AS
AS
= 4A, then E
2
IN
= 0.7μH
2μs/DIV
AS
OUT
= 5.6μJ. This is within
= 10μF
436112 F07
AS
) absorbed
11
IN
436112fa
dips
IN